Buttonhole



FIG. 1 is a front view of a buttonhole constructed according to my novel design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a bottom view thereof; and,

FIG. 6 is an exemplary drawing showing a plurality of buttonholes arranged on a shirt.

The broken lines showing of environmental structure in FIG. 6 of the drawings are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a buttonhole, as shown and described. 